Advice needed desperately

Rose asked 5 months ago

A man asked to be FWB with a woman he knew and both were married. He  told her early on that he wanted no emotions involved, had become cold and calloused and would probably never leave his wife and didn’t want to lose everything he for and to start over at 60 years old.  He kept meeting and texting her for a year, told her how badly he wanted to be alone with her for several hours, made plans to meet at least 10 times, but backed out every time at the last minute. He asked her to give him closure, if she didn’t want to continue and she promised she would. He also promised her closure because he knew how badly it hurt to be “thrown out” of someone’s life with no explanation, which nearly killed him. He has known this woman his entire life and thinks very highly of her. He told her that he thinks about her all the time and that she’s beautiful, fun, gorgeous, sexy and how easily he’s turned on by her. He told her recently that he always want to see her and, once again, made plans to meet at a hotel. She told him that if he backed out this time, she would never speak to him again, but then said she was joking. He texted her for a couple days. On Friday he texted her about how excited he was to meet her on Monday and the things he was going to do to her. Monday came and he told her that things weren’t looking good, so we rescheduled for Wednesday. Wednesday came, she texted hello to him. She gets a text from from him six hours later claiming that he thought all day long that it was Tuesday.  She wasn’t upset and asked if he wanted to meet her just to say hi and visit. He said he was already out of town, so she asked you if he wanted to meet the next day and he said yes.  The next day, she didn’t hear from him, so she texted to ask if he was okay and he didn’t reply. She hadn’t heard from him still, six days later, so she texted that she had NO idea what happened, but that he, of all people, knew how it felt to be rejected by someone he trusted and asked him to please at least keep one promise and give her closure. She also said that she was very sad and very confused.  A couple more weeks go by and she texted him again and said, “As usual, I’m clueless as to why you won’t talk to me.” Another week later, she sent a text that said, “PLEASE give me closure.”  To this day, he hasn’t replied to any of them and blocked her on Messenger, because he asked her in the past not to use Messenger, but she still does, if she HAS to make sure he got her message. He kept her as a friend on FB but he is never on there.
What do you think would cause him to act this way?